[systemd-devel] I want to use an environmental variable for LimitNOFILE= in a service unit. Is it possible?

[Tomasz Torcz]

On Thu, Sep 03, 2015 at 08:08:13PM +0300, Eliezer Croitoru wrote:
> I noticed it doesn't work.
> And well since I am building an RPM the only option I can think of is either
> use a custom startup script which will set the limits manually or define the
> service as a config file in the RPM.
> 
> Maybe you have some experience with overwriting the service files with RPMS,
> maybe there is some kind of practice use for this?
> 
> The main issue is that if I hardcode it in the service file the RPM will
> replace it each and every time.
> If I will use it as a config file it will stay the same and it might be the
> better solution.
> Seeking after thought and ideas on the best way to implement it.

  systemd come with quite cool system of unit precedence and is very
customisation-friendly for admin.  Just ship your unit in /usr/lib/systemd/system/
directory with default value of LimitNOFILE=.  If administrators want to
override, he will create dropin /etc/systemd/system/squid.service.d/10-limits.conf
with

–––
[Service]
LimitNOFILE=newvalue
–––

  and it will work fine during the upgrades.


-- 
Tomasz Torcz              ,,If you try to upissue this patchset I shall be seeking
xmpp: zdzichubg at chrome.pl   an IP-routable hand grenade.'' -- Andrew Morton (LKML)